A driver of a vehicle may want to operate a vehicle with side slip to compete in vehicle drifting completion or to show a high level of vehicle control. A vehicle may drift around a turn when a driver over steers and the vehicle's rear wheels slip such that the vehicle moves around a turn with its front wheels pointing in a direction away from the turn while the vehicle travels in the direction of the turn. A vehicle driver may find it difficult to induce and maintain side slip while controlling the vehicle's travel to a desired trajectory. Specifically, a vehicle driver may simultaneously manipulate a position of an accelerator pedal and a position of a steering wheel angle to induce vehicle side slip and control the vehicle's trajectory around a turn; however, the vehicle driver may find it difficult to maintain a proper balance of tire lateral forces at high vehicle sideslip angle. In addition, increased driver skill may be needed when response of the vehicle's driveline and driven axle wheel slip to changes in accelerator pedal position is slow. Further, the vehicle driver may observe little or no feedback of driven axle slip level feedback or a clear connection between steering wheel angle, vehicle sideslip angle, and driven wheel slip. Consequently, a vehicle driver that is less familiar with a particular vehicle or a vehicle driver that is unaccustomed to operating a vehicle with side slip, may find it difficult to induce vehicle side slip and direct a vehicle around a turn. Therefore, it may be desirable provide a vehicle system that assists a vehicle driver to initiate and control a vehicle side slip angle for drift cornering.
The inventors herein have recognized the above-mentioned issues and have developed a driveline operating method, comprising: receiving a steering angle and an accelerator pedal position to a controller; and adjusting output of driveline torque source to induce vehicle side slip via the controller in response to the steering angle being greater than a threshold angle and the accelerator pedal position being greater than a threshold position
By adjusting output of a driveline torque source in response to steering angle and accelerator pedal position, it may be possible to provide controlled vehicle side slip so that a vehicle may drift around corners of a closed track. In one example, output of an internal combustion engine and output of a rear drive unit electric machine may be increased as input from a human driver or automated driver increases steering angle input and accelerator pedal input. Further, rear drive unit electric machine output and internal combustion engine output may be limited or constrained so as to limit a vehicle side slip angle. In this way, vehicle side slip may be controlled so that vehicle side slip may be induced without providing a vehicle side slip angle that is greater than a threshold.
The present description may provide several advantages. For example, the approach may improve a vehicle driver's ability to induce and control a vehicle side slip angle. In addition, the approach may further improve a vehicle's capacity to enter a side slip condition via inducing transmission shift shock. Further, the approach may improve a vehicle's ability to enter a side slip condition and remain in the side slip condition via coordinated engine and electric machine torque.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.